The present invention relates to a distributed system connected to a network, and particularly to a highly reliable distributed system suitable for ensuring that message data is not damaged during send and receive processing of a message.
When a message is sent and received through a network, a network controller for implementing network communication by hardware and communication software for performing the network communication using the network controller are used. When data stored in an application program is sent, the data is written to the network controller through send protocol processing. When data is received, a message arrived at the network controller is written in the application program through receive protocol processing. As described above, the send and receive protocol processing between the application program and the network controller at sending and receiving data is processed using the communication software. When a bug exists in the communication software, when a register or a memory used by the communication software are damaged even if temporary, or when the content of data is changed by some reason, the content of data damaged by the send and receive protocol is sent or received. In order to ensure that the content of data is not damaged by the send and receive protocol, there is a method of using a plurality of versions of communication software implementing the same send and receive protocol processing created by a plurality of different persons. This method ensures that the content of data is not damaged by checking whether or not a result manipulated with send and receive protocol processing by one version of communication software agrees with a result manipulated with send and receive protocol processing by another version of communication software.
The above-mentioned prior art has a problem in that a plurality of versions of communication software need to be created.